Yield Components as Indirect Selection Criteria for Late-Planted Soybean Cultivars
- J. E. Board *a,
- M. S. Kanga and
- M. L. Bodrerob
Cultivar selection for late-planted soybean [Glycine max (L.) Merr.] in the wheat–soybean doublecropping system is an important production problem. Top-yielding cultivars for late plantings could be selected more efficiently by identification of yield components that indicate top yield, compared with the traditional combine-harvested plot yield method. Our objective was to identify yield components that could be used as indirect selection criteria to identify top-yielding cultivars for late planting dates. A 2-yr study (1998 and 1999) with 26 cultivars was conducted at a mid-July planting at Baton Rouge, LA (30° N, 90° W). A similar study involving 27 different cultivars was conducted for 1 yr at Los Oliveros, Santa Fe Province, Argentina (32°48′ S, 62° W), planted in early January 1999. Experimental designs were randomized complete blocks with four replications and one factor (cultivar). Data were obtained on combine-harvested plot yield, seed m−2, seed size, seed per pod, pods m−2, pods per reproductive node, and reproductive node m−2 Across years, yields at Baton Rouge ranged from 1183 to 2992 kg ha−1, while yields in Argentina ranged from 1688 to 2809 kg ha−1 Yield at Baton Rouge increased with maturity group, whereas in Argentina there was no relationship between yield and maturity group. For both phenotypic and genotypic levels, selection for either seed m−2 or pods m−2 identified top-yielding cultivars, although seed m−2 was more accurate.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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